what mass of Na2C2O4 was present initially

in a volumetric analysis experiment a solution of sodium oxalate ( Na2C2O4) in acidic solution is titrated with a solution of potassium permanganate according to the following balance chemical equation. 2KMnO4(aq) 8H2SO4(aq) 5 Na2C2O4(aq) _> 2MnSO4(aq) 8H2O(aq) 10CO2(g) 5 Na2SO4(aq) K2SO4(aq)it required 20 ml of 0.0147 MKnO4 to reach the end point. what mass of Na2C2O4 was present initially?